Annotation of OpenXM_contrib2/asir2000/gc5.3/alloc.c, Revision 1.1
1.1 ! noro 1: /*
! 2: * Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers
! 3: * Copyright (c) 1991-1996 by Xerox Corporation. All rights reserved.
! 4: * Copyright (c) 1998 by Silicon Graphics. All rights reserved.
! 5: * Copyright (c) 1999 by Hewlett-Packard Company. All rights reserved.
! 6: *
! 7: * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
! 8: * OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
! 9: *
! 10: * Permission is hereby granted to use or copy this program
! 11: * for any purpose, provided the above notices are retained on all copies.
! 12: * Permission to modify the code and to distribute modified code is granted,
! 13: * provided the above notices are retained, and a notice that the code was
! 14: * modified is included with the above copyright notice.
! 15: *
! 16: */
! 17:
! 18:
! 19: # include "gc_priv.h"
! 20:
! 21: # include <stdio.h>
! 22: # ifndef MACOS
! 23: # include <signal.h>
! 24: # include <sys/types.h>
! 25: # endif
! 26:
! 27: void GC_timerstart(),GC_timerstop();
! 28:
! 29: /*
! 30: * Separate free lists are maintained for different sized objects
! 31: * up to MAXOBJSZ.
! 32: * The call GC_allocobj(i,k) ensures that the freelist for
! 33: * kind k objects of size i points to a non-empty
! 34: * free list. It returns a pointer to the first entry on the free list.
! 35: * In a single-threaded world, GC_allocobj may be called to allocate
! 36: * an object of (small) size i as follows:
! 37: *
! 38: * opp = &(GC_objfreelist[i]);
! 39: * if (*opp == 0) GC_allocobj(i, NORMAL);
! 40: * ptr = *opp;
! 41: * *opp = obj_link(ptr);
! 42: *
! 43: * Note that this is very fast if the free list is non-empty; it should
! 44: * only involve the execution of 4 or 5 simple instructions.
! 45: * All composite objects on freelists are cleared, except for
! 46: * their first word.
! 47: */
! 48:
! 49: /*
! 50: * The allocator uses GC_allochblk to allocate large chunks of objects.
! 51: * These chunks all start on addresses which are multiples of
! 52: * HBLKSZ. Each allocated chunk has an associated header,
! 53: * which can be located quickly based on the address of the chunk.
! 54: * (See headers.c for details.)
! 55: * This makes it possible to check quickly whether an
! 56: * arbitrary address corresponds to an object administered by the
! 57: * allocator.
! 58: */
! 59:
! 60: word GC_non_gc_bytes = 0; /* Number of bytes not intended to be collected */
! 61:
! 62: word GC_gc_no = 0;
! 63:
! 64: #ifndef SMALL_CONFIG
! 65: int GC_incremental = 0; /* By default, stop the world. */
! 66: #endif
! 67:
! 68: int GC_full_freq = 19; /* Every 20th collection is a full */
! 69: /* collection, whether we need it */
! 70: /* or not. */
! 71:
! 72: GC_bool GC_need_full_gc = FALSE;
! 73: /* Need full GC do to heap growth. */
! 74:
! 75: word GC_used_heap_size_after_full = 0;
! 76:
! 77: char * GC_copyright[] =
! 78: {"Copyright 1988,1989 Hans-J. Boehm and Alan J. Demers ",
! 79: "Copyright (c) 1991-1995 by Xerox Corporation. All rights reserved. ",
! 80: "Copyright (c) 1996-1998 by Silicon Graphics. All rights reserved. ",
! 81: "THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY",
! 82: " EXPRESSED OR IMPLIED. ANY USE IS AT YOUR OWN RISK.",
! 83: "See source code for details." };
! 84:
! 85: # include "version.h"
! 86:
! 87: /* some more variables */
! 88:
! 89: extern signed_word GC_mem_found; /* Number of reclaimed longwords */
! 90: /* after garbage collection */
! 91:
! 92: GC_bool GC_dont_expand = 0;
! 93:
! 94: word GC_free_space_numerator = 1;
! 95: word GC_free_space_divisor = 3;
! 96:
! 97: extern GC_bool GC_collection_in_progress();
! 98: /* Collection is in progress, or was abandoned. */
! 99:
! 100: int GC_never_stop_func GC_PROTO((void)) { return(0); }
! 101:
! 102: CLOCK_TYPE GC_start_time; /* Time at which we stopped world. */
! 103: /* used only in GC_timeout_stop_func. */
! 104:
! 105: int GC_n_attempts = 0; /* Number of attempts at finishing */
! 106: /* collection within TIME_LIMIT */
! 107:
! 108: #ifdef SMALL_CONFIG
! 109: # define GC_timeout_stop_func GC_never_stop_func
! 110: #else
! 111: int GC_timeout_stop_func GC_PROTO((void))
! 112: {
! 113: CLOCK_TYPE current_time;
! 114: static unsigned count = 0;
! 115: unsigned long time_diff;
! 116:
! 117: if ((count++ & 3) != 0) return(0);
! 118: GET_TIME(current_time);
! 119: time_diff = MS_TIME_DIFF(current_time,GC_start_time);
! 120: if (time_diff >= TIME_LIMIT) {
! 121: # ifdef PRINTSTATS
! 122: GC_printf0("Abandoning stopped marking after ");
! 123: GC_printf1("%lu msecs", (unsigned long)time_diff);
! 124: GC_printf1("(attempt %d)\n", (unsigned long) GC_n_attempts);
! 125: # endif
! 126: return(1);
! 127: }
! 128: return(0);
! 129: }
! 130: #endif /* !SMALL_CONFIG */
! 131:
! 132: /* Return the minimum number of words that must be allocated between */
! 133: /* collections to amortize the collection cost. */
! 134: static word min_words_allocd()
! 135: {
! 136: # ifdef THREADS
! 137: /* We punt, for now. */
! 138: register signed_word stack_size = 10000;
! 139: # else
! 140: int dummy;
! 141: register signed_word stack_size = (ptr_t)(&dummy) - GC_stackbottom;
! 142: # endif
! 143: word total_root_size; /* includes double stack size, */
! 144: /* since the stack is expensive */
! 145: /* to scan. */
! 146: word scan_size; /* Estimate of memory to be scanned */
! 147: /* during normal GC. */
! 148:
! 149: if (stack_size < 0) stack_size = -stack_size;
! 150: total_root_size = 2 * stack_size + GC_root_size;
! 151: scan_size = BYTES_TO_WORDS(GC_heapsize - GC_large_free_bytes
! 152: + (GC_large_free_bytes >> 2)
! 153: /* use a bit more of large empty heap */
! 154: + total_root_size);
! 155: if (GC_incremental) {
! 156: return (scan_size*GC_free_space_numerator) / (2 * GC_free_space_divisor);
! 157: } else {
! 158: return (scan_size*GC_free_space_numerator) / GC_free_space_divisor;
! 159: }
! 160: }
! 161:
! 162: /* Return the number of words allocated, adjusted for explicit storage */
! 163: /* management, etc.. This number is used in deciding when to trigger */
! 164: /* collections. */
! 165: word GC_adj_words_allocd()
! 166: {
! 167: register signed_word result;
! 168: register signed_word expl_managed =
! 169: BYTES_TO_WORDS((long)GC_non_gc_bytes
! 170: - (long)GC_non_gc_bytes_at_gc);
! 171:
! 172: /* Don't count what was explicitly freed, or newly allocated for */
! 173: /* explicit management. Note that deallocating an explicitly */
! 174: /* managed object should not alter result, assuming the client */
! 175: /* is playing by the rules. */
! 176: result = (signed_word)GC_words_allocd
! 177: - (signed_word)GC_mem_freed - expl_managed;
! 178: if (result > (signed_word)GC_words_allocd) {
! 179: result = GC_words_allocd;
! 180: /* probably client bug or unfortunate scheduling */
! 181: }
! 182: result += GC_words_finalized;
! 183: /* We count objects enqueued for finalization as though they */
! 184: /* had been reallocated this round. Finalization is user */
! 185: /* visible progress. And if we don't count this, we have */
! 186: /* stability problems for programs that finalize all objects. */
! 187: result += GC_words_wasted;
! 188: /* This doesn't reflect useful work. But if there is lots of */
! 189: /* new fragmentation, the same is probably true of the heap, */
! 190: /* and the collection will be correspondingly cheaper. */
! 191: if (result < (signed_word)(GC_words_allocd >> 3)) {
! 192: /* Always count at least 1/8 of the allocations. We don't want */
! 193: /* to collect too infrequently, since that would inhibit */
! 194: /* coalescing of free storage blocks. */
! 195: /* This also makes us partially robust against client bugs. */
! 196: return(GC_words_allocd >> 3);
! 197: } else {
! 198: return(result);
! 199: }
! 200: }
! 201:
! 202:
! 203: /* Clear up a few frames worth of garbage left at the top of the stack. */
! 204: /* This is used to prevent us from accidentally treating garbade left */
! 205: /* on the stack by other parts of the collector as roots. This */
! 206: /* differs from the code in misc.c, which actually tries to keep the */
! 207: /* stack clear of long-lived, client-generated garbage. */
! 208: void GC_clear_a_few_frames()
! 209: {
! 210: # define NWORDS 64
! 211: word frames[NWORDS];
! 212: register int i;
! 213:
! 214: for (i = 0; i < NWORDS; i++) frames[i] = 0;
! 215: }
! 216:
! 217: /* Have we allocated enough to amortize a collection? */
! 218: GC_bool GC_should_collect()
! 219: {
! 220: return(GC_adj_words_allocd() >= min_words_allocd());
! 221: }
! 222:
! 223:
! 224: void GC_notify_full_gc()
! 225: {
! 226: if (GC_start_call_back != (void (*)())0) {
! 227: (*GC_start_call_back)();
! 228: }
! 229: }
! 230:
! 231: GC_bool GC_is_full_gc = FALSE;
! 232:
! 233: /*
! 234: * Initiate a garbage collection if appropriate.
! 235: * Choose judiciously
! 236: * between partial, full, and stop-world collections.
! 237: * Assumes lock held, signals disabled.
! 238: */
! 239: void GC_maybe_gc()
! 240: {
! 241: static int n_partial_gcs = 0;
! 242:
! 243: if (GC_should_collect()) {
! 244: if (!GC_incremental) {
! 245: GC_notify_full_gc();
! 246: GC_gcollect_inner();
! 247: n_partial_gcs = 0;
! 248: return;
! 249: } else if (GC_need_full_gc || n_partial_gcs >= GC_full_freq) {
! 250: # ifdef PRINTSTATS
! 251: GC_printf2(
! 252: "***>Full mark for collection %lu after %ld allocd bytes\n",
! 253: (unsigned long) GC_gc_no+1,
! 254: (long)WORDS_TO_BYTES(GC_words_allocd));
! 255: # endif
! 256: GC_promote_black_lists();
! 257: (void)GC_reclaim_all((GC_stop_func)0, TRUE);
! 258: GC_clear_marks();
! 259: n_partial_gcs = 0;
! 260: GC_notify_full_gc();
! 261: GC_is_full_gc = TRUE;
! 262: } else {
! 263: n_partial_gcs++;
! 264: }
! 265: /* We try to mark with the world stopped. */
! 266: /* If we run out of time, this turns into */
! 267: /* incremental marking. */
! 268: GET_TIME(GC_start_time);
! 269: if (GC_stopped_mark(GC_timeout_stop_func)) {
! 270: # ifdef SAVE_CALL_CHAIN
! 271: GC_save_callers(GC_last_stack);
! 272: # endif
! 273: GC_finish_collection();
! 274: } else {
! 275: if (!GC_is_full_gc) {
! 276: /* Count this as the first attempt */
! 277: GC_n_attempts++;
! 278: }
! 279: }
! 280: }
! 281: }
! 282:
! 283:
! 284: /*
! 285: * Stop the world garbage collection. Assumes lock held, signals disabled.
! 286: * If stop_func is not GC_never_stop_func, then abort if stop_func returns TRUE.
! 287: */
! 288: GC_bool GC_try_to_collect_inner(stop_func)
! 289: GC_stop_func stop_func;
! 290: {
! 291: if (GC_incremental && GC_collection_in_progress()) {
! 292: # ifdef PRINTSTATS
! 293: GC_printf0(
! 294: "GC_try_to_collect_inner: finishing collection in progress\n");
! 295: # endif /* PRINTSTATS */
! 296: /* Just finish collection already in progress. */
! 297: while(GC_collection_in_progress()) {
! 298: if (stop_func()) return(FALSE);
! 299: GC_collect_a_little_inner(1);
! 300: }
! 301: }
! 302: # ifdef PRINTSTATS
! 303: GC_printf2(
! 304: "Initiating full world-stop collection %lu after %ld allocd bytes\n",
! 305: (unsigned long) GC_gc_no+1,
! 306: (long)WORDS_TO_BYTES(GC_words_allocd));
! 307: # endif
! 308: GC_promote_black_lists();
! 309: /* Make sure all blocks have been reclaimed, so sweep routines */
! 310: /* don't see cleared mark bits. */
! 311: /* If we're guaranteed to finish, then this is unnecessary. */
! 312: /* In the find_leak case, we have to finish to guarantee that */
! 313: /* previously unmarked objects are not reported as leaks. */
! 314: if ((GC_find_leak || stop_func != GC_never_stop_func)
! 315: && !GC_reclaim_all(stop_func, FALSE)) {
! 316: /* Aborted. So far everything is still consistent. */
! 317: return(FALSE);
! 318: }
! 319: GC_invalidate_mark_state(); /* Flush mark stack. */
! 320: GC_clear_marks();
! 321: # ifdef SAVE_CALL_CHAIN
! 322: GC_save_callers(GC_last_stack);
! 323: # endif
! 324: GC_is_full_gc = TRUE;
! 325: if (!GC_stopped_mark(stop_func)) {
! 326: if (!GC_incremental) {
! 327: /* We're partially done and have no way to complete or use */
! 328: /* current work. Reestablish invariants as cheaply as */
! 329: /* possible. */
! 330: GC_invalidate_mark_state();
! 331: GC_unpromote_black_lists();
! 332: } /* else we claim the world is already still consistent. We'll */
! 333: /* finish incrementally. */
! 334: return(FALSE);
! 335: }
! 336: GC_finish_collection();
! 337: return(TRUE);
! 338: }
! 339:
! 340:
! 341:
! 342: /*
! 343: * Perform n units of garbage collection work. A unit is intended to touch
! 344: * roughly GC_RATE pages. Every once in a while, we do more than that.
! 345: * This needa to be a fairly large number with our current incremental
! 346: * GC strategy, since otherwise we allocate too much during GC, and the
! 347: * cleanup gets expensive.
! 348: */
! 349: # define GC_RATE 10
! 350: # define MAX_PRIOR_ATTEMPTS 1
! 351: /* Maximum number of prior attempts at world stop marking */
! 352: /* A value of 1 means that we finish the seconf time, no matter */
! 353: /* how long it takes. Doesn't count the initial root scan */
! 354: /* for a full GC. */
! 355:
! 356: int GC_deficit = 0; /* The number of extra calls to GC_mark_some */
! 357: /* that we have made. */
! 358:
! 359: void GC_collect_a_little_inner(n)
! 360: int n;
! 361: {
! 362: register int i;
! 363:
! 364: if (GC_incremental && GC_collection_in_progress()) {
! 365: for (i = GC_deficit; i < GC_RATE*n; i++) {
! 366: if (GC_mark_some((ptr_t)0)) {
! 367: /* Need to finish a collection */
! 368: # ifdef SAVE_CALL_CHAIN
! 369: GC_save_callers(GC_last_stack);
! 370: # endif
! 371: if (GC_n_attempts < MAX_PRIOR_ATTEMPTS) {
! 372: GET_TIME(GC_start_time);
! 373: if (!GC_stopped_mark(GC_timeout_stop_func)) {
! 374: GC_n_attempts++;
! 375: break;
! 376: }
! 377: } else {
! 378: (void)GC_stopped_mark(GC_never_stop_func);
! 379: }
! 380: GC_finish_collection();
! 381: break;
! 382: }
! 383: }
! 384: if (GC_deficit > 0) GC_deficit -= GC_RATE*n;
! 385: if (GC_deficit < 0) GC_deficit = 0;
! 386: } else {
! 387: GC_maybe_gc();
! 388: }
! 389: }
! 390:
! 391: int GC_collect_a_little GC_PROTO(())
! 392: {
! 393: int result;
! 394: DCL_LOCK_STATE;
! 395:
! 396: DISABLE_SIGNALS();
! 397: LOCK();
! 398: GC_collect_a_little_inner(1);
! 399: result = (int)GC_collection_in_progress();
! 400: UNLOCK();
! 401: ENABLE_SIGNALS();
! 402: return(result);
! 403: }
! 404:
! 405: /*
! 406: * Assumes lock is held, signals are disabled.
! 407: * We stop the world.
! 408: * If stop_func() ever returns TRUE, we may fail and return FALSE.
! 409: * Increment GC_gc_no if we succeed.
! 410: */
! 411: GC_bool GC_stopped_mark(stop_func)
! 412: GC_stop_func stop_func;
! 413: {
! 414: register int i;
! 415: int dummy;
! 416: # ifdef PRINTSTATS
! 417: CLOCK_TYPE start_time, current_time;
! 418: # endif
! 419:
! 420: STOP_WORLD();
! 421: GC_timerstart();
! 422: # ifdef PRINTSTATS
! 423: GET_TIME(start_time);
! 424: GC_printf1("--> Marking for collection %lu ",
! 425: (unsigned long) GC_gc_no + 1);
! 426: GC_printf2("after %lu allocd bytes + %lu wasted bytes\n",
! 427: (unsigned long) WORDS_TO_BYTES(GC_words_allocd),
! 428: (unsigned long) WORDS_TO_BYTES(GC_words_wasted));
! 429: # endif
! 430:
! 431: /* Mark from all roots. */
! 432: /* Minimize junk left in my registers and on the stack */
! 433: GC_clear_a_few_frames();
! 434: GC_noop(0,0,0,0,0,0);
! 435: GC_initiate_gc();
! 436: for(i = 0;;i++) {
! 437: if ((*stop_func)()) {
! 438: # ifdef PRINTSTATS
! 439: GC_printf0("Abandoned stopped marking after ");
! 440: GC_printf1("%lu iterations\n",
! 441: (unsigned long)i);
! 442: # endif
! 443: GC_timerstop();
! 444: GC_deficit = i; /* Give the mutator a chance. */
! 445: START_WORLD();
! 446: return(FALSE);
! 447: }
! 448: if (GC_mark_some((ptr_t)(&dummy))) break;
! 449: }
! 450:
! 451: GC_gc_no++;
! 452: # ifdef PRINTSTATS
! 453: GC_printf2("Collection %lu reclaimed %ld bytes",
! 454: (unsigned long) GC_gc_no - 1,
! 455: (long)WORDS_TO_BYTES(GC_mem_found));
! 456: GC_printf1(" ---> heapsize = %lu bytes\n",
! 457: (unsigned long) GC_heapsize);
! 458: /* Printf arguments may be pushed in funny places. Clear the */
! 459: /* space. */
! 460: GC_printf0("");
! 461: # endif
! 462:
! 463: /* Check all debugged objects for consistency */
! 464: if (GC_debugging_started) {
! 465: (*GC_check_heap)();
! 466: }
! 467:
! 468: # ifdef PRINTTIMES
! 469: GET_TIME(current_time);
! 470: GC_printf1("World-stopped marking took %lu msecs\n",
! 471: MS_TIME_DIFF(current_time,start_time));
! 472: # endif
! 473: GC_timerstop();
! 474: START_WORLD();
! 475: return(TRUE);
! 476: }
! 477:
! 478:
! 479: /* Finish up a collection. Assumes lock is held, signals are disabled, */
! 480: /* but the world is otherwise running. */
! 481: void GC_finish_collection()
! 482: {
! 483: # ifdef PRINTTIMES
! 484: CLOCK_TYPE start_time;
! 485: CLOCK_TYPE finalize_time;
! 486: CLOCK_TYPE done_time;
! 487:
! 488: GET_TIME(start_time);
! 489: finalize_time = start_time;
! 490: # endif
! 491: GC_timerstart();
! 492:
! 493: # ifdef GATHERSTATS
! 494: GC_mem_found = 0;
! 495: # endif
! 496: if (GC_find_leak) {
! 497: /* Mark all objects on the free list. All objects should be */
! 498: /* marked when we're done. */
! 499: {
! 500: register word size; /* current object size */
! 501: register ptr_t p; /* pointer to current object */
! 502: register struct hblk * h; /* pointer to block containing *p */
! 503: register hdr * hhdr;
! 504: register int word_no; /* "index" of *p in *q */
! 505: int kind;
! 506:
! 507: for (kind = 0; kind < GC_n_kinds; kind++) {
! 508: for (size = 1; size <= MAXOBJSZ; size++) {
! 509: for (p= GC_obj_kinds[kind].ok_freelist[size];
! 510: p != 0; p=obj_link(p)){
! 511: h = HBLKPTR(p);
! 512: hhdr = HDR(h);
! 513: word_no = (((word *)p) - ((word *)h));
! 514: set_mark_bit_from_hdr(hhdr, word_no);
! 515: }
! 516: }
! 517: }
! 518: }
! 519: GC_start_reclaim(TRUE);
! 520: /* The above just checks; it doesn't really reclaim anything. */
! 521: }
! 522:
! 523: GC_finalize();
! 524: # ifdef STUBBORN_ALLOC
! 525: GC_clean_changing_list();
! 526: # endif
! 527:
! 528: # ifdef PRINTTIMES
! 529: GET_TIME(finalize_time);
! 530: # endif
! 531:
! 532: /* Clear free list mark bits, in case they got accidentally marked */
! 533: /* Note: HBLKPTR(p) == pointer to head of block containing *p */
! 534: /* (or GC_find_leak is set and they were intentionally marked.) */
! 535: /* Also subtract memory remaining from GC_mem_found count. */
! 536: /* Note that composite objects on free list are cleared. */
! 537: /* Thus accidentally marking a free list is not a problem; only */
! 538: /* objects on the list itself will be marked, and that's fixed here. */
! 539: {
! 540: register word size; /* current object size */
! 541: register ptr_t p; /* pointer to current object */
! 542: register struct hblk * h; /* pointer to block containing *p */
! 543: register hdr * hhdr;
! 544: register int word_no; /* "index" of *p in *q */
! 545: int kind;
! 546:
! 547: for (kind = 0; kind < GC_n_kinds; kind++) {
! 548: for (size = 1; size <= MAXOBJSZ; size++) {
! 549: for (p= GC_obj_kinds[kind].ok_freelist[size];
! 550: p != 0; p=obj_link(p)){
! 551: h = HBLKPTR(p);
! 552: hhdr = HDR(h);
! 553: word_no = (((word *)p) - ((word *)h));
! 554: clear_mark_bit_from_hdr(hhdr, word_no);
! 555: # ifdef GATHERSTATS
! 556: GC_mem_found -= size;
! 557: # endif
! 558: }
! 559: }
! 560: }
! 561: }
! 562:
! 563:
! 564: # ifdef PRINTSTATS
! 565: GC_printf1("Bytes recovered before sweep - f.l. count = %ld\n",
! 566: (long)WORDS_TO_BYTES(GC_mem_found));
! 567: # endif
! 568: /* Reconstruct free lists to contain everything not marked */
! 569: GC_start_reclaim(FALSE);
! 570: if (GC_is_full_gc) {
! 571: GC_used_heap_size_after_full = USED_HEAP_SIZE;
! 572: GC_need_full_gc = FALSE;
! 573: } else {
! 574: GC_need_full_gc =
! 575: BYTES_TO_WORDS(USED_HEAP_SIZE - GC_used_heap_size_after_full)
! 576: > min_words_allocd();
! 577: }
! 578:
! 579: # ifdef PRINTSTATS
! 580: GC_printf2(
! 581: "Immediately reclaimed %ld bytes in heap of size %lu bytes",
! 582: (long)WORDS_TO_BYTES(GC_mem_found),
! 583: (unsigned long)GC_heapsize);
! 584: # ifdef USE_MUNMAP
! 585: GC_printf1("(%lu unmapped)", GC_unmapped_bytes);
! 586: # endif
! 587: GC_printf2(
! 588: "\n%lu (atomic) + %lu (composite) collectable bytes in use\n",
! 589: (unsigned long)WORDS_TO_BYTES(GC_atomic_in_use),
! 590: (unsigned long)WORDS_TO_BYTES(GC_composite_in_use));
! 591: # endif
! 592:
! 593: GC_n_attempts = 0;
! 594: GC_is_full_gc = FALSE;
! 595: /* Reset or increment counters for next cycle */
! 596: GC_words_allocd_before_gc += GC_words_allocd;
! 597: GC_non_gc_bytes_at_gc = GC_non_gc_bytes;
! 598: GC_words_allocd = 0;
! 599: GC_words_wasted = 0;
! 600: GC_mem_freed = 0;
! 601:
! 602: # ifdef USE_MUNMAP
! 603: GC_unmap_old();
! 604: # endif
! 605: # ifdef PRINTTIMES
! 606: GET_TIME(done_time);
! 607: GC_printf2("Finalize + initiate sweep took %lu + %lu msecs\n",
! 608: MS_TIME_DIFF(finalize_time,start_time),
! 609: MS_TIME_DIFF(done_time,finalize_time));
! 610: # endif
! 611: GC_timerstop();
! 612: }
! 613:
! 614: /* Externally callable routine to invoke full, stop-world collection */
! 615: # if defined(__STDC__) || defined(__cplusplus)
! 616: int GC_try_to_collect(GC_stop_func stop_func)
! 617: # else
! 618: int GC_try_to_collect(stop_func)
! 619: GC_stop_func stop_func;
! 620: # endif
! 621: {
! 622: int result;
! 623: DCL_LOCK_STATE;
! 624:
! 625: GC_INVOKE_FINALIZERS();
! 626: DISABLE_SIGNALS();
! 627: LOCK();
! 628: ENTER_GC();
! 629: if (!GC_is_initialized) GC_init_inner();
! 630: /* Minimize junk left in my registers */
! 631: GC_noop(0,0,0,0,0,0);
! 632: result = (int)GC_try_to_collect_inner(stop_func);
! 633: EXIT_GC();
! 634: UNLOCK();
! 635: ENABLE_SIGNALS();
! 636: if(result) GC_INVOKE_FINALIZERS();
! 637: return(result);
! 638: }
! 639:
! 640: void GC_gcollect GC_PROTO(())
! 641: {
! 642: GC_notify_full_gc();
! 643: (void)GC_try_to_collect(GC_never_stop_func);
! 644: }
! 645:
! 646: word GC_n_heap_sects = 0; /* Number of sections currently in heap. */
! 647:
! 648: /*
! 649: * Use the chunk of memory starting at p of size bytes as part of the heap.
! 650: * Assumes p is HBLKSIZE aligned, and bytes is a multiple of HBLKSIZE.
! 651: */
! 652: void GC_add_to_heap(p, bytes)
! 653: struct hblk *p;
! 654: word bytes;
! 655: {
! 656: word words;
! 657: hdr * phdr;
! 658:
! 659: if (GC_n_heap_sects >= MAX_HEAP_SECTS) {
! 660: ABORT("Too many heap sections: Increase MAXHINCR or MAX_HEAP_SECTS");
! 661: }
! 662: phdr = GC_install_header(p);
! 663: if (0 == phdr) {
! 664: /* This is extremely unlikely. Can't add it. This will */
! 665: /* almost certainly result in a 0 return from the allocator, */
! 666: /* which is entirely appropriate. */
! 667: return;
! 668: }
! 669: GC_heap_sects[GC_n_heap_sects].hs_start = (ptr_t)p;
! 670: GC_heap_sects[GC_n_heap_sects].hs_bytes = bytes;
! 671: GC_n_heap_sects++;
! 672: words = BYTES_TO_WORDS(bytes - HDR_BYTES);
! 673: phdr -> hb_sz = words;
! 674: phdr -> hb_map = (char *)1; /* A value != GC_invalid_map */
! 675: phdr -> hb_flags = 0;
! 676: GC_freehblk(p);
! 677: GC_heapsize += bytes;
! 678: if ((ptr_t)p <= GC_least_plausible_heap_addr
! 679: || GC_least_plausible_heap_addr == 0) {
! 680: GC_least_plausible_heap_addr = (ptr_t)p - sizeof(word);
! 681: /* Making it a little smaller than necessary prevents */
! 682: /* us from getting a false hit from the variable */
! 683: /* itself. There's some unintentional reflection */
! 684: /* here. */
! 685: }
! 686: if ((ptr_t)p + bytes >= GC_greatest_plausible_heap_addr) {
! 687: GC_greatest_plausible_heap_addr = (ptr_t)p + bytes;
! 688: }
! 689: }
! 690:
! 691: # if !defined(NO_DEBUGGING)
! 692: void GC_print_heap_sects()
! 693: {
! 694: register unsigned i;
! 695:
! 696: GC_printf1("Total heap size: %lu\n", (unsigned long) GC_heapsize);
! 697: for (i = 0; i < GC_n_heap_sects; i++) {
! 698: unsigned long start = (unsigned long) GC_heap_sects[i].hs_start;
! 699: unsigned long len = (unsigned long) GC_heap_sects[i].hs_bytes;
! 700: struct hblk *h;
! 701: unsigned nbl = 0;
! 702:
! 703: GC_printf3("Section %ld from 0x%lx to 0x%lx ", (unsigned long)i,
! 704: start, (unsigned long)(start + len));
! 705: for (h = (struct hblk *)start; h < (struct hblk *)(start + len); h++) {
! 706: if (GC_is_black_listed(h, HBLKSIZE)) nbl++;
! 707: }
! 708: GC_printf2("%lu/%lu blacklisted\n", (unsigned long)nbl,
! 709: (unsigned long)(len/HBLKSIZE));
! 710: }
! 711: }
! 712: # endif
! 713:
! 714: ptr_t GC_least_plausible_heap_addr = (ptr_t)ONES;
! 715: ptr_t GC_greatest_plausible_heap_addr = 0;
! 716:
! 717: ptr_t GC_max(x,y)
! 718: ptr_t x, y;
! 719: {
! 720: return(x > y? x : y);
! 721: }
! 722:
! 723: ptr_t GC_min(x,y)
! 724: ptr_t x, y;
! 725: {
! 726: return(x < y? x : y);
! 727: }
! 728:
! 729: # if defined(__STDC__) || defined(__cplusplus)
! 730: void GC_set_max_heap_size(GC_word n)
! 731: # else
! 732: void GC_set_max_heap_size(n)
! 733: GC_word n;
! 734: # endif
! 735: {
! 736: GC_max_heapsize = n;
! 737: }
! 738:
! 739: GC_word GC_max_retries = 0;
! 740:
! 741: /*
! 742: * this explicitly increases the size of the heap. It is used
! 743: * internally, but may also be invoked from GC_expand_hp by the user.
! 744: * The argument is in units of HBLKSIZE.
! 745: * Tiny values of n are rounded up.
! 746: * Returns FALSE on failure.
! 747: */
! 748: GC_bool GC_expand_hp_inner(n)
! 749: word n;
! 750: {
! 751: word bytes;
! 752: struct hblk * space;
! 753: word expansion_slop; /* Number of bytes by which we expect the */
! 754: /* heap to expand soon. */
! 755:
! 756: if (n < MINHINCR) n = MINHINCR;
! 757: bytes = n * HBLKSIZE;
! 758: /* Make sure bytes is a multiple of GC_page_size */
! 759: {
! 760: word mask = GC_page_size - 1;
! 761: bytes += mask;
! 762: bytes &= ~mask;
! 763: }
! 764:
! 765: if (GC_max_heapsize != 0 && GC_heapsize + bytes > GC_max_heapsize) {
! 766: /* Exceeded self-imposed limit */
! 767: return(FALSE);
! 768: }
! 769: space = GET_MEM(bytes);
! 770: if( space == 0 ) {
! 771: return(FALSE);
! 772: }
! 773: # ifdef PRINTSTATS
! 774: GC_printf2("Increasing heap size by %lu after %lu allocated bytes\n",
! 775: (unsigned long)bytes,
! 776: (unsigned long)WORDS_TO_BYTES(GC_words_allocd));
! 777: # ifdef UNDEFINED
! 778: GC_printf1("Root size = %lu\n", GC_root_size);
! 779: GC_print_block_list(); GC_print_hblkfreelist();
! 780: GC_printf0("\n");
! 781: # endif
! 782: # endif
! 783: expansion_slop = 8 * WORDS_TO_BYTES(min_words_allocd());
! 784: if (5 * HBLKSIZE * MAXHINCR > expansion_slop) {
! 785: expansion_slop = 5 * HBLKSIZE * MAXHINCR;
! 786: }
! 787: if (GC_last_heap_addr == 0 && !((word)space & SIGNB)
! 788: || GC_last_heap_addr != 0 && GC_last_heap_addr < (ptr_t)space) {
! 789: /* Assume the heap is growing up */
! 790: GC_greatest_plausible_heap_addr =
! 791: GC_max(GC_greatest_plausible_heap_addr,
! 792: (ptr_t)space + bytes + expansion_slop);
! 793: } else {
! 794: /* Heap is growing down */
! 795: GC_least_plausible_heap_addr =
! 796: GC_min(GC_least_plausible_heap_addr,
! 797: (ptr_t)space - expansion_slop);
! 798: }
! 799: GC_prev_heap_addr = GC_last_heap_addr;
! 800: GC_last_heap_addr = (ptr_t)space;
! 801: GC_add_to_heap(space, bytes);
! 802: #if defined(VISUAL_LIB)
! 803: SendHeapSize();
! 804: #endif
! 805: return(TRUE);
! 806: }
! 807:
! 808: /* Really returns a bool, but it's externally visible, so that's clumsy. */
! 809: /* Arguments is in bytes. */
! 810: # if defined(__STDC__) || defined(__cplusplus)
! 811: int GC_expand_hp(size_t bytes)
! 812: # else
! 813: int GC_expand_hp(bytes)
! 814: size_t bytes;
! 815: # endif
! 816: {
! 817: int result;
! 818: DCL_LOCK_STATE;
! 819:
! 820: DISABLE_SIGNALS();
! 821: LOCK();
! 822: if (!GC_is_initialized) GC_init_inner();
! 823: result = (int)GC_expand_hp_inner(divHBLKSZ((word)bytes));
! 824: if (result) GC_requested_heapsize += bytes;
! 825: UNLOCK();
! 826: ENABLE_SIGNALS();
! 827: return(result);
! 828: }
! 829:
! 830: unsigned GC_fail_count = 0;
! 831: /* How many consecutive GC/expansion failures? */
! 832: /* Reset by GC_allochblk. */
! 833:
! 834: GC_bool GC_collect_or_expand(needed_blocks, ignore_off_page)
! 835: word needed_blocks;
! 836: GC_bool ignore_off_page;
! 837: {
! 838: if (!GC_incremental && !GC_dont_gc &&
! 839: (GC_dont_expand && GC_words_allocd > 0 || GC_should_collect())) {
! 840: GC_notify_full_gc();
! 841: GC_gcollect_inner();
! 842: } else {
! 843: word blocks_to_get = (GC_heapsize*GC_free_space_numerator)/(HBLKSIZE*GC_free_space_divisor)
! 844: + needed_blocks;
! 845:
! 846: if (blocks_to_get > MAXHINCR) {
! 847: word slop;
! 848:
! 849: if (ignore_off_page) {
! 850: slop = 4;
! 851: } else {
! 852: slop = 2*divHBLKSZ(BL_LIMIT);
! 853: if (slop > needed_blocks) slop = needed_blocks;
! 854: }
! 855: if (needed_blocks + slop > MAXHINCR) {
! 856: blocks_to_get = needed_blocks + slop;
! 857: } else {
! 858: blocks_to_get = MAXHINCR;
! 859: }
! 860: }
! 861: if (!GC_expand_hp_inner(blocks_to_get)
! 862: && !GC_expand_hp_inner(needed_blocks)) {
! 863: if (GC_fail_count++ < GC_max_retries) {
! 864: WARN("Out of Memory! Trying to continue ...\n", 0);
! 865: GC_notify_full_gc();
! 866: GC_gcollect_inner();
! 867: } else {
! 868: WARN("Out of Memory! Returning NIL!\n", 0);
! 869: return(FALSE);
! 870: }
! 871: } else {
! 872: # ifdef PRINTSTATS
! 873: if (GC_fail_count) {
! 874: GC_printf0("Memory available again ...\n");
! 875: }
! 876: # endif
! 877: }
! 878: }
! 879: return(TRUE);
! 880: }
! 881:
! 882: /*
! 883: * Make sure the object free list for sz is not empty.
! 884: * Return a pointer to the first object on the free list.
! 885: * The object MUST BE REMOVED FROM THE FREE LIST BY THE CALLER.
! 886: * Assumes we hold the allocator lock and signals are disabled.
! 887: *
! 888: */
! 889: ptr_t GC_allocobj(sz, kind)
! 890: word sz;
! 891: int kind;
! 892: {
! 893: register ptr_t * flh = &(GC_obj_kinds[kind].ok_freelist[sz]);
! 894:
! 895: if (sz == 0) return(0);
! 896:
! 897: #if defined(VISUAL)
! 898: {
! 899: #include <signal.h>
! 900: extern int recv_intr;
! 901: if ( recv_intr ) {
! 902: if ( recv_intr == 1 ) {
! 903: recv_intr = 0;
! 904: int_handler();
! 905: } else {
! 906: recv_intr = 0;
! 907: ox_usr1_handler(0);
! 908: }
! 909: }
! 910: }
! 911: #endif
! 912: while (*flh == 0) {
! 913: ENTER_GC();
! 914: /* Do our share of marking work */
! 915: if(GC_incremental && !GC_dont_gc) GC_collect_a_little_inner(1);
! 916: /* Sweep blocks for objects of this size */
! 917: GC_continue_reclaim(sz, kind);
! 918: EXIT_GC();
! 919: if (*flh == 0) {
! 920: GC_new_hblk(sz, kind);
! 921: }
! 922: if (*flh == 0) {
! 923: ENTER_GC();
! 924: if (!GC_collect_or_expand((word)1,FALSE)) {
! 925: EXIT_GC();
! 926: return(0);
! 927: }
! 928: EXIT_GC();
! 929: }
! 930: }
! 931:
! 932: return(*flh);
! 933: }
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